The present invention relates to determining the shape of surfaces of soft tissue, and more specifically, to determining such shapes using optical technology. Hearing aids, hearing protection, and custom head phones often require silicone impressions to be made of a patient's ear canal. Audiologists inject the silicone material into an ear, wait for it to harden, and then provide the mold to manufacturers who use the resulting silicone impression to create a custom fitting in-ear device. The process is slow, expensive, inconsistent, unpleasant for the patient, and can even be dangerous, as injecting silicone risks affecting the ear drum. Also, there are a range of other medical needs that benefit from determining the shape of body surfaces, including surfaces defining body orifices, such as the size of shape of an ear canal, throat, mouth, nostrils, or intestines of a patient. For example, surgery may be guided by knowing such shapes or medical devices fashioned to have a custom fit for such shapes.